A distributing valve of the above-mentioned type is known from EP 0,093,359 A1 which is incorporated herein by reference. In EP 0,093,359 A1, the distributing valve consists of a valve body, within which a displaceable actuating member is arranged along an axis thereof, and which can be actuated by displacement of the member by a pair of housings for the control apparatus located opposite each other, with respect to the axis of the valve body. The valve body consists of a tub-shaped housing which can be closed with a flat cover. The body is provided with ISO standard gas connection ports on the side opposite the cover, i.e., the bottom. The control housings of EP 0,093,359 A1, however, lie outside the tub-shaped valve body. This has the disadvantage that the control housings must be mounted separately and, in this connection, also suitably separately sealed. The actuating member of EP 0,093,359 A1 is a longitudinally moveable control slide, which is guided in a multipartite slide bushing within the housing. The multipartite structure in the region of the valve body, which guides the actuating member, increases the cost of assembly of the valve.
Another distributing valve is known from EP 0,134,185 which is incorporated herein by reference. The distributing valve of EP 0,134,185 consists of a valve-body housing containing a plurality of valve chambers, spaced parallel to each other in a lateral direction. These valve chambers are formed from segments, which can be joined together, and each of which is provided with an opening. The openings are aligned with a common axis which forms the axis of movement of the moveable valve member guided in the valve chambers. A pair of control housings lie opposite each other with respect to the axis, facing outward in axial direction. The valve member is, in this case, actuated via the control housings by displacement in an axial direction into the desired positions.
The valve member itself in EP 0,134,185 consists of a bar having radial symmetry, which is tapered in various sections so that a gas is passed or blocked between the valve chambers depending on the position of the valve member. The valve member resides in a valve body housing with valve chambers and control housings, which is assembled with screws onto a valve base plate. The critical sealing surfaces, including the sealing surface between the valve member and the valve chambers and the sealing surface of the entire valve-chamber system, are formed by individual sealing elements or sealing rings. This has the disadvantage that the valve consists of a plurality of individual elements, which makes both assembly and maintenance especially difficult and time consuming.
Another valve is known from Federal Republic of Germany DE-OS 1,915,966, which is incorporated herein by reference. In DE-OS 1,915,966, the valve consists of a coherent valve body which has valve chambers and within which there is an opening which extends axially through all of the valve chambers. A valve member having radial symmetry is displaceably guided through this opening. This arrangement, however, makes it difficult to obtain a suitable seal between the individual regions of the valve member and the valve chambers. The valve body is, in this case, fastened on a base body having suitable gas connections. A partially surrounding protective hood is connected over the assembly consisting of the valve body and the base body. This has the disadvantage that the control housings which actuate the valve member are arranged outside of the protective hood, and as a result of which the entire valve is more difficult to handle upon assembly.